Subscriber Discussion

Issue With Smart Codecs And Time Lapse Recording In Exacq

CW
Craig Wilson
•Mar 22, 2018

I noticed something unusual in exacq vision and was wondering if anyone has come across this yet. I have a mix of Axis and Hikvision cameras on the latest firmware and I am running the latest version of exacq. The system time lapse is set for 1 IPS with the camera jumping up to 10-15 IPS on motion. Whats happening is the time lapse portion ends up being a single image every 20-40 seconds instead of every 1-3 seconds as it should. I have this problem with all the sites I have running the smart codecs from Axis and Hikvision. I was wondering if anyone else has had this issue before or has a dealt with it before I reach out to exacq on it.  

(1)
U
Undisclosed #1
•Mar 22, 2018

In more traditional time lapse videos the time between images is longer than 1 second. My guess is that the feature is designed to grab a key frame once every X seconds, but if the time between keyframes is longer than that, then the best it'll do is give you keyframes. It's computationally expensive to process the stream to build a complete image from the last keyframe and the other frames in between, and with smart codecs, the time between keyframes can vary quite a lot.

I'd check with Exacq to confirm, and see if they have a way to override that behavior. Maybe the time lapse could be done using an alternate stream?

(2)
(1)
CW
Craig Wilson
•Mar 22, 2018
In reply to Undisclosed #1

I agree, but in order to maintain constant recording without burning a ton of storage, one would like to record at 1 image every 1-3 seconds to give you a continuous recording. I submitted a ticket to exacq and we will see what they come back with. 

U
Undisclosed #1
•Mar 22, 2018
In reply to Craig Wilson

Wouldn't the use of smart codecs mostly negate the need for different motion vs non-motion frame rates? They should send very little data during no motion. But I suppose if the motion detection is region based due to constant movement from trees/cars, this might be a good alternative.

(1)
UM
Undisclosed Manufacturer #2
•Mar 22, 2018

 If your VMS supports dual streaming, can you record the secondary profile for the time lapse, and turn off the smart codec on that frame? This way you still get the smart codec for high activity periods.

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Avatar
Ethan Ace
•Mar 22, 2018
In reply to Undisclosed Manufacturer #2

Hikvision models don't allow for a full resolution secondary stream, so it won't work. I just checked that as well. 

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SK
Sebastian Kratzke
•Mar 22, 2018

The problem is exactly what you get when smart codecs use dynamic framerate and dynamic GOP length and a VMS only saves I-frames for timelapse.

CW
Craig Wilson
•Mar 22, 2018

After a call with exacq and making it through the various support levels, my initial suspicions were correct in the way that the smart codecs do things, by adjusting the max dynamic GOP length from 300 to 75 achieved the result i was looking for in the time lapse, but at probably at a significant bandwidth and storage loss. I haven't yet figured out how to do it with the Hikvision, as the smart codec reports state, there is not much in the lines of settings one can tweak on a Hikvision. 

 

  

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